A method for integrating and transmitting partial discharge optical signals based on optical coupling

Abstract

The application discloses a kind of based on light coupling partial discharge light signal integration and transmission method, it is related to signal integration and transmission technical field.The method comprises the following steps: constructing single-ended input-multichannel output optical fiber collection topology, collecting the fluorescence optical fiber output signal of each area;Signal merging is carried out to the multiple fluorescence optical fiber output signal, and a group of reference light source pulses is injected to each collection channel at fixed interval;Output signal intensity variation trend and channel self-calibration reference table, dynamically configure the gain parameter of photomultiplier preamplifier stage;After the electric signal that is converted by photoelectricity and preamplification adjustment is input high-speed analog-digital converter and sampling, and is carried out convolution fitting and time domain enhancement processing, according to the fluorescence optical fiber output signal of collection channel corresponding.This application has the advantages of high efficiency, error suppression ability, high detection sensitivity and so on, is suitable for the partial discharge monitoring and fault diagnosis under the complex structure in high-voltage switchgear and other power equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of signal integration and transmission, and particularly relates to a partial discharge optical signal integration and transmission method based on optical coupling. BACKGROUND

[0002] In the operation of a power system, a switch cabinet is a key device for power distribution and control, and the stability of the insulation state is crucial to the safety of the power grid. Partial discharge is an early typical feature of insulation degradation of high-voltage equipment, which is a short-term discharge phenomenon caused by local electric field concentration in the insulating medium. Long-term persistence can accelerate insulation aging and even cause equipment failure or power outage accidents. Therefore, it is of great significance to monitor the partial discharge of the switch cabinet in real time. Traditional detection methods such as the pulse current method and the ultrasonic method are easily affected by electromagnetic interference and environmental noise, and it is difficult to achieve high-precision measurement in the high-voltage and strong electromagnetic coupling switch cabinet. Optical fiber sensing technology has become an ideal choice for partial discharge detection in high-voltage environments due to its advantages of anti-electromagnetic interference, good insulation, small size, and long-distance transmission. The fluorescence optical fiber sensor uses sensitive materials such as rare earth-doped optical fibers and fluorescent polymers to excite the fluorescence optical fiber output signal under the action of electric field or ultraviolet light and heat generated by discharge, and effectively avoids the influence of electromagnetic interference on the detection results.

[0003] For example, CN111308289 discloses a partial discharge multi-spectral weak light detection device and method, which uses a condenser lens and a filter to couple multi-band optical signals, uses a photodetector array to convert the optical signals into multi-channel current signals, and calculates the intensity ratio of the optical pulse signals through a signal processing module and a diagnosis module to identify the type and severity of partial discharge. This scheme has high detection sensitivity and good anti-electromagnetic interference ability, and is suitable for partial discharge monitoring in power equipment. However, it has the following disadvantages: (1) This scheme relies on a fixed-position photodetector array and lacks flexibility in deploying distributed and heterogeneous areas, making it difficult to adapt to the multi-region and non-homogeneous distribution of high-risk partial discharge points in actual engineering; (2) In signal acquisition, the inconsistent gain problem of multi-channel signals in the transmission and fusion process is not considered, which may cause some weak signals to be masked in the background of strong signals; (3) No effective dynamic gain control mechanism and channel trend calibration strategy are provided, and there is a lack of intelligent collaboration method for channel response consistency and sampling control, thereby limiting the improvement of overall discrimination accuracy.

[0004] CN111624449B discloses a multi-channel optical detection system for partial discharge of power equipment based on emission spectroscopy. The system collects partial discharge optical radiation signals through optical fibers and uses optical fiber couplers to split the signals. Then, it extracts characteristic spectral bands through narrowband filters and high-sensitivity photodetectors. The analog signals are converted by A / D and sent to a remote monitoring computer for optical analysis and diagnosis. This method can realize multi-channel parallel detection and is suitable for multi-point synchronous monitoring. Although this technology has certain practical value in characteristic spectral band extraction and remote data processing, it still has the following shortcomings: (1) The method adopts a beam splitting acquisition structure, that is, a main signal source is distributed to multiple channels. This structure is difficult to achieve true regional independent signal acquisition when facing multiple high-risk areas of partial discharge, which is not conducive to fine positioning; (2) It lacks an inter-channel calibration mechanism and dynamic gain matching, and cannot adaptively adjust the response differences between channels, resulting in the analysis results depending on the preset threshold and poor adaptability; (3) The system does not build a sampling control mechanism based on time-series behavior, which makes it difficult to effectively capture short-term weak partial discharge events, and there is a risk of response lag and misidentification. Summary of the Invention

[0005] In view of the problems existing in the partial discharge monitoring of multi-switch cabinets, this invention is proposed.

[0006] Therefore, the problem to be solved by this invention is how to achieve unified enhancement and collaborative judgment of multi-channel signals.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] In a first aspect, the present invention provides a method for integrating and transmitting partial discharge optical signals based on optical coupling. The method includes: attaching fluorescent fiber optic sensing units to multiple high-risk partial discharge areas and constructing a single-end input-multi-channel output fiber optic acquisition topology to collect the fluorescent fiber optic output signals from each area; setting centralized optical coupling nodes at the output ends of all acquisition channels to merge the multiple fluorescent fiber optic output signals, injecting a set of reference light source pulses to each acquisition channel at fixed intervals, recording the corresponding responses, and establishing a channel self-calibration reference table; dynamically configuring the gain parameters of the photomultiplier tube preamplifier stage based on the intensity variation trend of the fluorescent fiber optic output signals and the channel self-calibration reference table, while matching the instantaneous response range of discharges of different intensities; inputting the electrical signals after photoelectric conversion and preamplifier gain adjustment into a high-speed analog-to-digital converter for sampling, performing convolution fitting and time-domain enhancement processing, and generating a switchgear discharge discrimination tag and assigning a device number based on the fluorescent fiber optic output signals corresponding to the acquisition channels.

[0009] As a preferred embodiment of the optical coupling-based partial discharge optical signal integration and transmission method of the present invention, the determination of the high-risk area of ​​partial discharge includes: acquiring a three-dimensional structural model of the switchgear chamber and generating a spatial positioning dataset of the surface of each insulating component by combining the actual arrangement information of the insulating components; based on the spatial positioning dataset, identifying structural feature units with potential partial discharge hazards, including: insulating protrusions located between the angles of conductors with different potentials; non-uniform surface areas with sharp corners, grooves or irregular edges; and weak insulation coverage areas close to the surface of the metal shell or ground potential conductor; marking each type of structural feature as a set of independent layers, superimposing different layers using intersection logic, and retaining only the areas that appear simultaneously in two or more sets of structural features, marking them as cross-verification areas as high-risk areas of partial discharge.

[0010] As a preferred embodiment of the optical coupling-based partial discharge optical signal integration and transmission method of the present invention, the centralized optical coupling node adopts a multi-end fused taper process or an integrated optical waveguide structure to construct an optical fiber aggregation structure with wavelength matching capability and spatial channel isolation performance, for interference-free convergence transmission of multi-channel signals.

[0011] As a preferred embodiment of the optical coupling-based partial discharge optical signal integration and transmission method of the present invention, the step of combining the output signals of multiple fluorescent optical fibers and injecting a set of reference light source pulses to each acquisition channel at fixed intervals includes: guiding the single-end output of each fluorescent optical fiber to a preset centralized optical coupling node, with each output end corresponding to a physical access port in the optical coupling node, and the port arrangement being based on the optical path length and spectral coupling consistency; guiding the output signals of each fluorescent optical fiber into a common aggregation optical path to achieve single-channel output of multi-channel signals; generating stable reference pulses during the signal acquisition interval according to the master control time sequence, and connecting them to the centralized optical coupling node near the acquisition end of each fluorescent optical fiber through optical splitters, so that each fluorescent optical fiber channel receives a standard reference light source pulse within the reference pulse injection time window.

[0012] As a preferred embodiment of the optical coupling-based partial discharge optical signal integration and transmission method of the present invention, the method comprises: extracting the stability factors of multidimensional factors of the corresponding acquisition channel within different time windows in the current period based on the continuous response waveform of the fluorescent fiber output signal in each acquisition channel, forming a stability feature vector; and constructing a stability score matrix by combining the set of stability feature vectors of all acquisition channels; calling the historical stability factor feature vector of the corresponding acquisition channel in the channel self-calibration reference table, and calculating the trend change vector of the current channel in multidimensional factors through the continuous stability feature vector in the current period; performing a trend consistency comparison with the corresponding multidimensional factor sequence in the historical reference vector based on the trend change vector, and calculating the trend offset score by combining fluctuation deviation and structural residual; and determining the gain correction coefficient of the current channel based on the trend offset score amplitude, and configuring the gain parameters of the photomultiplier tube preamplifier stage through the gain adjustment function. .

[0013] As a preferred embodiment of the partial discharge optical signal integration and transmission method based on optical coupling described in this invention, the gain adjustment function includes:

[0014]

[0015] in, The initial reference gain for the acquisition channel. This is the gain sensitivity adjustment factor. Score the trend deviation.

[0016] As a preferred embodiment of the optical coupling-based partial discharge optical signal integration and transmission method of the present invention, the step of inputting the electrical signal after photoelectric conversion and pre-gain adjustment into a high-speed analog-to-digital converter for sampling, and performing convolution fitting and temporal enhancement processing includes: after photoelectric conversion and gain adjustment, constructing a sampling control index table based on the current channel acquisition state and self-calibration reference table; under the drive of the sampling control index table, triggering the high-speed analog-to-digital converter to sample channel by channel sequentially; calling the response template structure marked in the channel self-calibration reference table to perform photoelectric conversion and gain adjustment processing. After adjustment, the sampled electrical signal segments of each acquisition channel obtained by the high-speed analog-to-digital converter are subjected to nonparametric template convolution fitting processing: the response template structure is slid over time; the sliding analysis window segment in the sampled electrical signal segment and the response template structure are compared in terms of the degree of fit of the response leading edge, main peak position and tail shape; if the degree of fit exceeds the lower limit of the matching strength, it is marked as a valid response segment, and the following three-stage time domain enhancement processing is performed: local smoothing and boundary interpolation are performed on short-time abrupt waveforms; the weight of the rising segment of the leading edge is increased; the main peak segment is reconstructed to suppress the fluctuation spikes caused by sampling errors.

[0017] As a preferred embodiment of the optical coupling-based partial discharge optical signal integration and transmission method of the present invention, the degree of fit includes: setting the sliding window length, extracting local segments in the sampled electrical signal segment with a fixed step size, and obtaining a total of multiple local windows; for each local segment, performing multi-factor matching and alignment comparison with the standard template structure in the channel self-calibration reference table, and expressing it using a multi-factor weighted combination method.

[0018] In a second aspect, the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program instructions are executed by the processor, they implement the steps of the method for integrating and transmitting partial discharge optical signals based on optical coupling as described in the first aspect of the present invention.

[0019] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program instructions are executed by a processor, the steps of the method for integrating and transmitting partial discharge optical signals based on optical coupling as described in the first aspect of the present invention are implemented.

[0020] The beneficial effects of this invention are as follows: This invention uses a centralized optical coupling node to fuse multi-channel signals and establishes a channel self-calibration reference table through a fixed injected reference light source pulse, thereby achieving consistency correction and stability calibration of the responses between channels; by dynamically configuring the pre-gain of the photomultiplier tube, the acquisition sensitivity is adaptively adjusted according to the weak fluctuation characteristics of the fluorescence signal, improving the detection resolution of partial discharge events of different intensities; furthermore, by performing convolution fitting and time-domain enhancement processing, the synchronous analysis of multi-channel signals and the time-domain enhancement of weak signals are effectively realized, improving the reliability and timeliness of discharge signal identification.

[0021] This invention has the advantages of high efficiency in signal integration, strong error suppression capability, and high detection sensitivity. It is suitable for partial discharge monitoring and fault diagnosis in complex structures of power equipment such as high-voltage switchgear, and has good prospects for engineering applications. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart of a partial discharge optical signal integration and transmission method based on optical coupling;

[0024] Figure 2This is a schematic diagram of a four-in-one coupling unit for a partial discharge optical signal integration and transmission method based on optical coupling.

[0025] Figure 3 Comparison of time-domain signals between single-output fluorescent fiber and four-in-one output based on optical coupling;

[0026] Figure 4 A comparison of discharge characteristics between single-output fluorescent fiber and four-in-one output based on optical coupling. Detailed Implementation

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0029] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0030] As mentioned in the background section, traditional detection methods such as pulsed current methods and ultrasonic methods are susceptible to electromagnetic interference and environmental noise, making it difficult to achieve high-precision measurements inside high-voltage, strongly electromagnetically coupled switchgear. Fiber optic sensing technology, with its advantages of resistance to electromagnetic interference, good insulation, small size, and long-distance transmission capability, has become an ideal choice for partial discharge detection in high-voltage environments. Fluorescent fiber optic sensors utilize rare-earth-doped optical fibers, fluorescent polymers, and other sensitive materials. Under the influence of an electric field or ultraviolet light and heat generated by discharge, the fluorescent fiber optic output signal is excited, converting the weak partial discharge signal into an optical signal output, effectively avoiding the influence of electromagnetic interference on the detection results.

[0031] Example 1

[0032] Figure 1 This is a flowchart illustrating a method for integrating and transmitting partial discharge optical signals based on optical coupling, according to an embodiment of the present invention. Figure 1 As shown, the method for integrating and transmitting partial discharge optical signals based on optical coupling includes:

[0033] S1: Attach fluorescent fiber optic sensing units to multiple high-risk areas of partial discharge and construct a single-end input-multi-channel output fiber optic acquisition topology to collect the fluorescent fiber optic output signal of each area.

[0034] Specifically, a three-dimensional structural model of the switchgear chamber is obtained, and combined with the actual arrangement information of the insulation components, a spatial positioning dataset of the surface of each insulation component is generated.

[0035] Based on the spatial positioning dataset, the following three types of structural feature units with potential partial discharge hazards were identified: (1) Insulation protrusions located between the angles of conductors with different potentials; (2) Non-uniform surface areas with sharp corners, grooves or irregular edges; (3) Insulation coverage areas close to the surface of metal shells or ground potential conductors.

[0036] Each type of structural feature is labeled as an independent layer. Intersection logic is used to overlay different layers / datasets. For example, an edge extraction algorithm based on discrete curvature is used to identify concave and convex regions, and potential distribution mapping is used to screen regions where the electric field intensity exceeds a threshold. Each type of structural risk factor is formed into an independent structural feature layer. An intersection overlay algorithm is used to perform Boolean intersection operations on all layers, retaining only regions that appear simultaneously in two or more structural feature sets. These are marked as cross-verification regions, serving as high-risk areas for partial discharge. A list of high-risk area identifiers is established to guide the attachment and deployment of fluorescent fiber optic sensing units.

[0037] For example, if a region has both sharp corner features and is close to a metal shell, then the region is more likely to be induced by local discharge due to electric field concentration or potential unevenness. This treatment method does not require manual intervention and can be performed entirely by structural modeling software, field simulation system or spatial analysis engine (such as COMSOL, ANSYS, ArcGIS, AutoCAD, etc.).

[0038] S1.2: A fluorescent fiber optic sensing unit is attached to a high-risk area, wherein one end of the fluorescent fiber optic sensing unit is attached close to an insulating structure to collect the fluorescent fiber optic output signal generated by partial discharge excitation.

[0039] S1.3: Lead out the other end of each fluorescent fiber sensing unit to construct a single-end input multi-channel acquisition structure for corresponding acquisition of fluorescent fiber output signals from multiple high-risk areas.

[0040] Its core lies in the construction of a highly efficient signal link of "single-end acquisition - centralized coupling - single-fiber transmission": each fluorescent fiber independently monitors the corresponding switch cabinet, the signal output from the single end is enhanced by optical field coherent superposition at the coupling node to enhance the signal-to-noise ratio, and the low-loss transmission fiber ensures long-distance distortion-free transmission of the signal.

[0041] This design retains the ability to monitor each switch cabinet independently, while simplifying system wiring through a four-in-one output, reducing the hardware cost and complexity of synchronous acquisition of multiple signals, and providing a highly integrated, low-power technical solution for large-scale monitoring of partial discharge in multiple switch cabinets.

[0042] This invention proposes using four fluorescent optical fibers deployed in four independent switch cabinets to collect fluorescence signals induced by partial discharge in each cabinet. After signal modulation, the signals are combined into a single signal via an optical coupler and finally output to the back-end demodulation system through a single optical fiber. This invention leverages the optical characteristics of the fluorescent optical fiber sensor, making it resistant to interference in strong electromagnetic environments. During signal transmission, the optical signal propagates in the fiber through total internal reflection, fundamentally avoiding electromagnetic coupling interference. The integration of four independent detection signals into a single optical fiber output via optical coupling technology significantly simplifies the system architecture and reduces wiring complexity and hardware costs. It enables synchronous detection of multiple switch cabinets, distinguishing signals from different channels using time-division or wavelength-division multiplexing techniques, and locating the discharge position and assessing the discharge intensity using back-end signal demodulation algorithms. Furthermore, optical fiber transmission has low loss and long lifespan, and the sensor has no electrical connection to high-voltage equipment, avoiding the safety hazards of traditional electrical measurement methods and improving system reliability.

[0043] S2: Set a centralized optical coupling node at the output end of all acquisition channels, merge the signals of multiple fluorescent fiber outputs, and inject a set of reference light source pulses into each acquisition channel at fixed intervals, record the corresponding response and establish a channel self-calibration reference table.

[0044] S2.1: Guide the single-end output of each fluorescent fiber to a preset centralized optical coupling node. Each output corresponds to a physical access port in the optical coupling node. The port arrangement is based on the consistency of optical path length and spectral coupling (e.g., optical path length difference ≤ 10mm (compensated by adjustable delay line), center wavelength deviation of each channel ≤ ±5nm, and -3dB spectral width difference ≤ 15%), to ensure that the spatial position of different fluorescent fiber outputs is consistent with the beam distribution.

[0045] Centralized optical coupling nodes include: integrating a low-loss optical aggregation structure into the optical coupling node, using fused taper or integrated waveguide bundling technology to guide the output signals of each fluorescent fiber into a common aggregation optical path, thereby realizing single-channel output of multi-channel signals.

[0046] S2.2: Based on the master control time sequence, a stable reference pulse is generated during the signal acquisition interval, and connected to the coupling point near the acquisition end of each fluorescent fiber through an optical splitter, so that each fluorescent fiber channel receives the standard reference light source pulse within a predetermined time window.

[0047] The specific operation is as follows: First, the dual-phase timing is divided in the main control processing module. The acquisition phase shuts down the reference light source and acquires the partial discharge signal; the calibration phase generates a standard light source pulse (pulse width 50-200ns / center wavelength matched to the fluorescence band / intensity fluctuation <±1%). To prevent aliasing interference between the partial discharge signal and the reference pulse, the acquisition and calibration phases are strictly interleaved in the timing control, and an interval protection time window is set to ensure that no discharge signal acquisition operation is performed on any channel during the reference pulse injection period, thereby avoiding signal superposition and misjudgment.

[0048] The standard light source pulse, after being output by the modulation module, is evenly distributed to multiple branch channels. To ensure that each fluorescent fiber channel receives the reference light pulse under the same physical conditions, a basic fiber length measurement module is installed in the main optical path, and a multi-channel optical splitter with equal-length fiber delay lines is configured on this basis to dynamically compensate for the differences in the basic path of each channel. A coupling point is then connected to the end of each branch. This coupling point is preferably located at a physical distance from the target fluorescent fiber acquisition end, and dynamic compensation is performed in conjunction with the differences in the basic optical path length to approximately ensure optical path symmetry and path consistency.

[0049] This structural design allows for real-time calibration of the response baseline for each acquisition channel, as well as simultaneous acquisition of time delay, response intensity variations, and reflection interference within the optical path. In the signal post-processing stage, based on the response data of each channel to a standard light source pulse, a channel response reference value for the current system state can be automatically generated. Furthermore, the partial discharge-induced response in the acquired signal can be normalized, drift corrected, and gain adjusted, significantly improving the stability and reliability of subsequent detection and analysis.

[0050] Meanwhile, this reference injection mechanism also constitutes one of the aging detection methods. If a significant shift is found in the response of a certain acquisition channel to the standard reference pulse, it can be determined that the fluorescent fiber of that channel is aging, the connection is loose, or the coupling efficiency is declining, providing an early warning for system maintenance.

[0051] S2.3: Label and manage the output ends of all fluorescent optical fibers and guide them to the coupling node in the same direction. Insert them sequentially into the preset multi-end optical interface slots to form a multi-channel ingress structure. Through consistent numbering and physical alignment calibration, ensure that the optical signal of each channel has a corresponding mapping relationship, meeting the requirements for subsequent calibration and channel identification.

[0052] In the specific operation, each fluorescent fiber is first assigned a unique number in the fiber optic integrated interface. For example, the numbering rule can be "Cab-X_Ch-Y", where X represents the switch cabinet number and Y represents the channel number within that cabinet. All numbers are directly marked on the connector sheath or fiber optic pigtail using laser engraving or hot-pressing labels to avoid lost or misplaced markings.

[0053] Next, insert all fluorescent fiber outputs into the multi-channel physical interface slots of the centralized optical coupling node in numerical order. The position of each slot must be precisely planned in advance using CAD drawings, and a stop locator must be set to ensure consistent insertion depth and high fiber core alignment accuracy. Simultaneously, the slot number should be automatically identified by the system's main control module, and each physical interface number should be logically mapped by software to the acquisition system channel logical address.

[0054] In addition, to ensure the consistency between physical arrangement and optical path transmission, this invention designs a bidirectional alignment calibration mechanism: (1) During the initial insertion stage, the coaxiality of the optical axis can be determined by laser light transmission test, and the slot angle or fiber core connector can be adjusted; (2) After startup, the response time offset between channels can be verified by reference light source injection test. If the deviation exceeds the deviation threshold, a warning prompt to reconnect is triggered; the operation ultimately forms a channel self-calibration reference table, which can be dynamically updated with the system operation status.

[0055] S3: Based on the trend of fluorescence fiber output signal intensity change and the channel self-calibration reference table, dynamically configure the gain parameters of the photomultiplier tube preamplifier stage, and match the instantaneous response range of different discharge intensities.

[0056] S3.1: Based on the continuous response waveform of the fluorescent fiber output signal in each acquisition channel within the current multi-cycle period, extract the stability factors of the multi-dimensional factors in different time windows of the corresponding acquisition channel within the current cycle, and construct the stability feature vector. The set of stability feature vectors of all acquisition channels constitutes the stability scoring matrix.

[0057] Since the instantaneous light intensity, waveform duration, spectral distribution, and peak position of the fluorescent fiber signal can all reflect the discharge excitation intensity and coupling transmission state during the excitation response process, this invention selects the following four core dimensions as factors to construct stability features: mean light intensity, peak position offset, signal envelope change rate, and the degree of change in time-domain oscillation trend (wavelet packet energy distribution or sliding window local frequency fitting can be used instead of the concentration of the main frequency distribution).

[0058] The above four dimensions are used to extract local features through a sliding time window method (e.g., setting 3 adjacent sampling periods, each containing 1000 sampling points), and are calculated one by one according to the channel number to form a four-dimensional stability vector for each channel. Taking N channels as an example, the final result is an N×4-dimensional stability scoring matrix, where each column vector represents the stability feature state of the i-th acquisition channel in the current period.

[0059] S3.2: Call the historical stability factor feature vector of the corresponding acquisition channel in the channel self-calibration reference table, and calculate the trend change vector of the current channel on the multi-dimensional factors through the continuous stability feature vector in the current period.

[0060] The specific operation is as follows: Each acquisition channel is equipped with a set of historical stability vector sliding window recording sequences, for example, using a time series of length M, where each vector is a 4-dimensional stability feature of the corresponding time period. By constructing trend change vectors, the drift intensity and direction of the current period signal in the stability space can be quantified.

[0061] This operation is equivalent to treating the current period as a new state point in the signal disturbance response space, and using the historical state average as a benchmark to calculate indicators such as the Euclidean distance and the direction cosine angle.

[0062] The drift intensity is reflected in the overall deviation amplitude (L2 norm), while the directional change is reflected in the vector angle (cosθ). The results of the vector analysis will be used for subsequent trend offset score calculations.

[0063] The multidimensional trend vector analysis mechanism proposed in this invention can effectively distinguish between long-term drift caused by changes in system state (such as temperature, aging, and loose connections) and short-term drastic jumps caused by fluctuations in discharge intensity, thereby constructing a more physically meaningful and diagnostic regulatory feedback system.

[0064] S3.3: Based on the trend change vector, perform a trend consistency comparison with the corresponding multi-dimensional factor sequence in the historical reference vector, and calculate the trend deviation score by combining the fluctuation deviation (such as the mean square error) and structural residual (such as the vector offset rate).

[0065] Specifically, for each channel, the following three types of comparison analysis are performed:

[0066] Compare the directional shift of the current vector direction with the historical average direction;

[0067] The average standard deviation of the current periodic vector and the vectors in the historical sequence measures the degree of instability of the instantaneous response;

[0068] The distance between the current vector and the historical mean, divided by the historical standard deviation, is used as a standardized measure of relative offset.

[0069] The above indicators are combined and weighted to generate a trend deviation score.

[0070] If the trend offset score exceeds the set adjustment threshold, the gain correction coefficient for the current channel is determined based on the trend offset score amplitude, and the gain parameters of the photomultiplier tube preamplifier stage are configured through the gain adjustment function. .

[0071] The gain adjustment function includes:

[0072]

[0073] in, The initial reference gain for the acquisition channel. This is the gain sensitivity adjustment factor. A trend offset score is given. The gain sensitivity adjustment factor can be calculated by dividing the amplifier's dynamic adjustment sensitivity constant by the channel stability variance.

[0074] The above adjustment function design ensures that in When the gain approaches zero, the gain remains constant; when When the gain is increased, the system automatically increases the amplification factor to match the response and capture requirements of low-intensity or short-duration partial discharge signals, thereby improving the weak signal identification capability. Conversely, if the trend offset score shifts significantly in the negative direction, the gain can be reduced symmetrically to avoid saturation distortion of high-intensity signals.

[0075] Compared to traditional fixed-gain systems, this invention achieves active matching and adjustment of the nonlinear response range of fluorescent optical fibers through a trend-driven dynamic gain configuration mechanism without increasing additional hardware complexity, thereby improving the system's recognition tolerance and dynamic response accuracy under multiple discharge events.

[0076] S4: The electrical signal after photoelectric conversion and pre-gain adjustment is input into the high-speed analog-to-digital converter and sampled. Convolution fitting and time-domain enhancement processing are performed. Based on the fluorescent fiber output signal corresponding to the acquisition channel, a switch cabinet discharge discrimination tag is generated and a device number is assigned.

[0077] S4.1: After photoelectric conversion and gain adjustment, construct a sampling control index table based on the current channel acquisition status and self-calibration reference table.

[0078] This invention proposes a sampling control index table mechanism as the central management structure for sampling scheduling. The index table is constructed based on basic information such as the acquisition channel number, sampling start timestamp, sampling duration, sampling frequency, and expected signal strength range.

[0079] The construction of the sampling control index table needs to refer to the current acquisition channel status information, including but not limited to: the current periodic amplification gain value, fluorescence output intensity level, channel stability score, and historical response pattern type. It is used to dynamically synchronize channel status and adapt sampling strategies, ensuring that sampling scheduling remains reasonable even when channel status deviates slightly. For example, if the response signal strength of a certain acquisition channel is weak but the trend deviation score is high, the index table will automatically increase the sampling frequency and extend the sampling duration to ensure that the response segment is completely acquired.

[0080] It should be noted that the sampling control index table, as the basic structure of sampling scheduling, ensures that the sampling logic and response state evolve together, avoiding invalid sampling caused by channel drift.

[0081] S4.2: Driven by the sampling control index table, the high-speed analog-to-digital converter (ADC) is triggered to sample channel by channel sequentially. Each acquisition channel uses a fixed duration and an equally spaced sampling frequency. The sampling length is dynamically adjusted based on the response duration in the previous cycle to avoid truncating or overextending short-term abnormal fluctuations. During the initial system startup phase, since there are no historical cycles to refer to, the first cycle sampling is performed using the set default sampling duration, and the response characteristics of the first cycle are recorded simultaneously as a benchmark for subsequent dynamic adjustments. The default sampling duration is set, and the response duration boundary threshold is defined.

[0082] Here, fixed duration refers to the physical time window of the sampling period; sampling length refers to the number of data points collected within the fixed duration according to the sampling frequency. Therefore, under a fixed duration, sampling length = sampling frequency × sampling duration. If the sampling duration is variable or the sampling frequency is dynamically adjustable, then the sampling length is also a variable.

[0083] Furthermore, the sampling length is dynamically adjusted based on the response duration in the previous period, including:

[0084] From the enhanced processing results of the previous cycle, read the start and end timestamps of the effective response segment for each acquisition channel, and calculate the actual response duration. ;

[0085] Set the default sampling duration And define the response duration boundary threshold. ;

[0086] like If so, it is considered a short fluctuation;

[0087] like If so, it is considered an extended discharge response.

[0088] based on and The comparison results show that if the response is too short, the compressed sampling time is... If the response is too long, the sampling window is expanded to avoid missing key wake portions; among which, This provides a buffer time to prevent boundary truncation.

[0089] Recalculate the number of sampling points per channel in this period. ,in, Set the sampling frequency and update the sampling index table.

[0090] S4.3: Call the response template structure marked in the channel self-calibration reference table, and perform nonparametric template convolution fitting on the sampled electrical signal segment of each channel obtained after photoelectric conversion and gain adjustment and then sampled by the high-speed analog-to-digital converter in the following order:

[0091] Time-by-time sliding response template structure;

[0092] Compare the degree of fit between the sliding analysis window segment and the response template structure in the sampled electrical signal segment in terms of response front, main peak position and tail shape.

[0093] Specifically, a sliding window length is set, and local segments are extracted by sliding in the sampled electrical signal segment with a fixed step size, resulting in a total of multiple local windows. For each local segment, it is aligned and compared with the standard template structure in the channel self-calibration reference table. The following multi-factor matching indicators can be used: peak position offset degree, rising edge slope matching degree, tail persistence overlap rate, waveform overall normalized cosine similarity, etc. (these can be set according to actual operation, and the embodiments of this invention do not impose a unique limitation). The final matching degree index can be expressed by a weighted combination method.

[0094] If the degree of fit exceeds the lower limit of matching strength, it is marked as a valid response segment and included in the subsequent enhancement process.

[0095] It can be seen that the convolution process of this invention does not rely on a numerical function model, but performs matching based on the reference structure contour, thereby enhancing the system's ability to identify nonlinear disturbance signals.

[0096] S4.4: Perform temporal enhancement processing in the matching segment.

[0097] For each segment determined to have a valid response after convolutional fitting, the following three-stage temporal augmentation process is performed:

[0098] First-order local smoothing (such as Savitzky-Golay filtering) and boundary interpolation compensation are performed on short-term fluctuation segments to improve waveform boundary continuity;

[0099] Increase the weight of the rising edge to enhance the ability to distinguish weak initial response signals;

[0100] The main peak segment is reconstructed, and wavelet packet decomposition and principal component replacement methods are used to perform noise filtering and enhancement on the main peak segment, eliminating spike interference and enhancing the stability of the peak structure.

[0101] It can be seen that the present invention improves the effectiveness of the original amplified signal at the feature identification level and solves the problem that weak partial discharge events are masked by short-term interference.

[0102] S4.5: Extract feature indicators and generate discriminant labels.

[0103] For the enhanced signal segment, the following indicators are extracted to form a discharge behavior feature vector: the rate of change of fluorescence fiber output signal intensity, response duration, peak offset position, leading edge slope stability, and tail fluctuation amplitude.

[0104] The aforementioned feature vectors are fed into the discharge feature discrimination template to generate discharge intensity level labels, response confidence scores, and device number binding information under the channel unique identifier; the final output constitutes a discharge discrimination label-device number pair, forming a stable result delivery structure.

[0105] This embodiment also provides a computer device applicable to the method of integrating and transmitting partial discharge optical signals based on optical coupling, including a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to realize the method of integrating and transmitting partial discharge optical signals based on optical coupling as proposed in the above embodiment.

[0106] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0107] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the method for integrating and transmitting partial discharge optical signals based on optical coupling as proposed in the above embodiments.

[0108] Example 2

[0109] In embodiments of the present invention, such as Figure 2 As shown, a fluorescent fiber optic sensing architecture with single-ended input and four-in-one output was designed to meet the partial discharge monitoring requirements of four switch cabinets, achieving efficient convergence and single-fiber transmission of four independent detection signals.

[0110] Specifically, each switch cabinet is equipped with a fluorescent optical fiber with a diameter of 1 mm and a length of 20 cm. One end serves as a signal acquisition end, which is close to the insulating components inside the switch cabinet to capture the fluorescent signal excited by partial discharge. The other end (single-ended output) is connected to the main transmission optical fiber through high-precision optical fiber fusion splicing technology or an optical coupler.

[0111] The single-ended output ends of the four fluorescent optical fibers (corresponding to the four switch cabinets respectively) are combined at the coupling node using a fused taper process or an integrated optical coupler. This couples the four independent optical signals (with the same center wavelength or distinguished by wavelength division multiplexing technology) to a low-loss transmission optical fiber with a diameter of 3 mm and a length of 2 m, forming a "4-in-1" single-fiber output structure.

[0112] This design breaks through the complex mode of parallel transmission of multiple optical fibers in traditional multi-channel monitoring. Each fluorescent optical fiber only needs to output to the coupling node at one end, avoiding the structural complexity of dual-end acquisition. Through a specially designed four-port optical coupler (coupling efficiency ≥95%), the discharge signals of the four switch cabinets can achieve energy superposition without crosstalk, and are transmitted to the back-end photomultiplier tube (PMT) via a single transmission optical fiber.

[0113] The signal processing stage uses a high-sensitivity PMT such as the Hamamatsu R928. The multi-stage dynode structure can amplify the photon signal by more than 106 times. Combined with a high-speed oscilloscope with a bandwidth of 500 MHz and a sampling rate of 5GS / s, it can accurately capture nanosecond-level partial discharge transient signals.

[0114] This experiment was designed with a progressive logic: after setting up the experimental platform, a single switch cabinet was used as the object, with defects set inside it, and signals were collected through a single-input single-output system; then the experimental object was expanded to four switch cabinets, with defects arranged in each cabinet, and signals were first collected by four independent single-input single-output systems, and then by a four-in-one integrated system; finally, the performance differences of different signal acquisition systems were explored by comparing multiple sets of data.

[0115] like Figure 3 and Figure 4 The figure shows a comparison of time-domain signals and characteristic quantities between single-output and four-in-one output. Experimental data shows that, compared with the scheme of transmitting and demodulating four independent optical fibers separately, the architecture of this invention improves the detection sensitivity of weak discharge signals by about 20% to 30% through signal combining effect, while reducing the amount of transmission optical fiber and the number of detector interfaces by 75%.

[0116] In summary, this invention employs a centralized optical coupling node to fuse multi-channel signals and establishes a channel self-calibration reference table using a fixed injected reference light source pulse, achieving consistency correction and stability calibration of inter-channel responses. By dynamically configuring the pre-gain of the photomultiplier tube, the acquisition sensitivity is adaptively adjusted according to the weak fluctuation characteristics of the fluorescence signal, improving the detection resolution for partial discharge events of different intensities. Furthermore, by performing convolution fitting and temporal enhancement processing, synchronous analysis of multi-channel signals and temporal enhancement of weak signals are effectively achieved, improving the reliability and timeliness of discharge signal identification.

[0117] The overall method has advantages such as high efficiency in signal integration, strong error suppression capability, and high detection sensitivity. It is suitable for partial discharge monitoring and fault diagnosis in complex structures of power equipment such as high-voltage switchgear, and has good prospects for engineering applications.

[0118] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for integrating and transmitting partial discharge optical signals based on optical coupling, characterized in that: include: Fluorescent fiber optic sensing units were attached to multiple high-risk areas of partial discharge, and a single-ended input-multi-channel output fiber optic acquisition topology was constructed to collect the fluorescent fiber optic output signal of each area. A centralized optical coupling node is set at the output end of all acquisition channels to combine the signals of multiple fluorescent fiber outputs, and a set of reference light source pulses are injected into each acquisition channel at fixed intervals. The corresponding response is recorded and a channel self-calibration reference table is established. Based on the trend of fluorescence fiber output signal intensity variation and the channel self-calibration reference table, the gain parameters of the photomultiplier tube preamplifier stage are dynamically configured, while matching the instantaneous response range of discharges of different intensities. The electrical signal after photoelectric conversion and pre-gain adjustment is input into a high-speed analog-to-digital converter and sampled. Convolution fitting and time-domain enhancement processing are performed. Based on the fluorescent fiber output signal corresponding to the acquisition channel, a switch cabinet discharge discrimination tag is generated and an equipment number is assigned. The process of inputting the electrical signal after photoelectric conversion and pre-gain adjustment into a high-speed analog-to-digital converter for sampling, and performing convolution fitting and time-domain enhancement processing includes: after photoelectric conversion and gain adjustment, constructing a sampling control index table based on the current channel acquisition status and self-calibration reference table; under the drive of the sampling control index table, triggering the high-speed analog-to-digital converter to sample channel by channel sequentially; calling the response template structure marked in the channel self-calibration reference table to perform non-parametric template convolution fitting processing on the sampled electrical signal segments of each acquisition channel obtained after photoelectric conversion and gain adjustment and sampled by the high-speed analog-to-digital converter: sliding the response template structure step by step; comparing the degree of fit between the sliding analysis window segment in the sampled electrical signal segment and the response template structure in the response leading edge, main peak position and tail shape; if the degree of fit exceeds the lower limit of matching strength, it is marked as a valid response segment, and the following three-stage time-domain enhancement processing is performed: performing local smoothing and boundary interpolation on short-time abrupt waveforms; increasing the weight of the rising segment of the leading edge; reconstructing the main peak segment and suppressing the fluctuation spikes caused by sampling errors.

2. The method for integrating and transmitting partial discharge optical signals based on optical coupling as described in claim 1, characterized in that: The determination of the high-risk area for partial discharge includes: A three-dimensional structural model of the switchgear chamber is obtained, and combined with the actual layout information of the insulation components, a spatial positioning dataset of the surface of each insulation component is generated. Based on the spatial positioning dataset, structural feature units with potential partial discharge hazards are identified, including: insulation protrusion areas located between the angles of conductors with different potentials; non-uniform surface areas with sharp corners, grooves, or irregular edges; and areas with weak insulation coverage close to the surface of the metal shell or ground potential conductor. Each type of structural feature is marked as a set of independent layers. Different layers are superimposed using intersection logic. Only the regions that appear simultaneously in two or more sets of structural features are retained and marked as cross-verification regions, which are considered high-risk areas for partial discharge.

3. The method for integrating and transmitting partial discharge optical signals based on optical coupling as described in claim 1, characterized in that: The centralized optical coupling node adopts a multi-end fused taper process or an integrated optical waveguide structure to construct an optical fiber aggregation structure with wavelength matching capability and spatial channel isolation performance, which is used for interference-free convergence transmission of multi-channel signals.

4. The method for integrating and transmitting partial discharge optical signals based on optical coupling as described in claim 3, characterized in that: The step of combining the multi-channel fluorescent fiber output signals and injecting a set of reference light source pulses into each acquisition channel at fixed intervals includes: The single-end output of each fluorescent fiber is guided to a preset centralized optical coupling node. Each output corresponds to a physical access port in the optical coupling node. The port arrangement is based on the optical path length and spectral coupling consistency. The output signals from each fluorescent fiber are fed into a common aggregation optical path to achieve single-channel output of multi-channel signals; Stable reference pulses are generated during the signal acquisition intervals based on the master control time sequence, and are connected to the centralized optical coupling nodes of each fluorescent fiber acquisition end through optical splitters, so that each fluorescent fiber channel receives the standard reference light source pulse within the reference pulse injection time window.

5. The method for integrating and transmitting partial discharge optical signals based on optical coupling as described in claim 1, characterized in that: The gain parameters of the dynamically configured photomultiplier tube preamplifier stage include: Based on the continuous response waveform of the fluorescent fiber output signal in each acquisition channel within the current multi-cycle period, the stability factors of the multi-dimensional factors in different time windows of the corresponding acquisition channel within the current cycle are extracted to form a stability feature vector. The set of stability feature vectors of all acquisition channels constitutes a stability scoring matrix. The historical stability factor feature vector of the corresponding acquisition channel is called in the channel self-calibration reference table. The trend change vector of the current channel in the multi-dimensional factors is calculated through the continuous stability feature vector in the current period. Based on the trend change vector, a trend consistency comparison is performed with the corresponding multi-dimensional factor sequence in the historical reference vector. Combined with volatility deviation and structural residual, a weighted trend deviation score is calculated. If the trend offset score exceeds the set adjustment threshold, the gain correction coefficient for the current channel is determined based on the trend offset score amplitude, and the gain parameters of the photomultiplier tube preamplifier stage are configured through the gain adjustment function. .

6. The method for integrating and transmitting partial discharge optical signals based on optical coupling as described in claim 5, characterized in that: The gain adjustment function includes: in, The initial reference gain for the acquisition channel. This is the gain sensitivity adjustment factor. Score the trend deviation.

7. The method for integrating and transmitting partial discharge optical signals based on optical coupling as described in claim 6, characterized in that: Compatibility includes: Set the sliding window length and use a fixed step size to slide and extract local segments in the sampled electrical signal segment, resulting in a total of multiple local windows; For each local segment, a multi-factor matching and alignment comparison is performed with the standard template structure in the channel self-calibration reference table, and the result is expressed using a multi-factor weighted combination method.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the partial discharge optical signal integration and transmission method based on optical coupling as described in any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the partial discharge optical signal integration and transmission method based on optical coupling as described in any one of claims 1 to 7.

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